I use MC on one of my systems with 3 displays. My middle monitor has the little menu bar "hat" attached to it in Mac System Preferences > Displays. I think that designates it as "primary" in some way.
With most programs (Safari, Calendar, Slack, etc) the menu bar follows the window. Put the window on the left monitor, and the menu bar works on the left. Put the window on the right monitor and you can use the menu bar on the right, as you would expect.
But MC is different. The menu bar appears on whatever display you place MC on. But the menu bar does not work. If you click, it turns grey. What it seems to be saying is "hey I'm over here on the primary monitor". If you use the menu bar on the middle monitor, it works. In fact the menu bar appears on the middle monitor too, even when the MC window is on the left or right monitor. Control works from the middle monitor menu bar. But not from any other monitor. I can use this, but it's very awkward and strange.
Similarly, right click menus. I often right click on an album cover and do "add to playing now". Or other similar actions. Interestingly this works a few times. Perhaps 3 times in a row. Then MC decides "no more of that" and the menu will never appear again until MC is restarted. I can right click over and over again and nothing happens. BUT... if I move MC to the middle monitor (primary) the right click menu works as expected, every single time. So I've resorted to moving MC temporarily, doing my right click stuff, and then moving it back to the monitor where it belongs.
I presume these behaviors are related, but perhaps not.
Thanks for reading.
Brian.